The stated and observed levels of quality control will be assessed in 100 dental offices by monthly sensitometric studies over the course of a year. In addition, a full mouth series of films developed by each office will be compared with identical films processed under ideal conditions of quality control. To evaluate the effect of processing quality on diagnostic and treatment planning decisions, each of the two investigators will examine 100 patients, one using radiographs processed by one of the experimental offices, the other using duplicate films processed at the insitution. The distribution of experimental or control films will be done randomly. Detection of dental disease such as caries defective restorations, periapical pathology, and periodontal pathology will be compared for experimental and control images, with special emphasis on level and type of quality control. Discrepancies in diagnosis and treatment plans by standardized and calibrated examiners may be attributed to variations in processing quality. These variations may be measured qualitatively and quantitatively and used to construct a cost benefit analysis of radiographic quality assurance programs. A major question to be addressed is: Are differences in diagnostic quality of films produced with inadequate or absent quality control sufficient to justify the cost of implementing or improving quality assurance programs. As many as 20% of intraoral radiographs may not be readable because of improper processing. Little information is available about minimal standards of quality assurance required for production of diagnostic images. Correlation of measured levels of QA with stated practice will be helpful in augmenting, direction revision, or prioritizing QA guidelines suggested in 1983 by the American Academy of Dental Radiology. Ultimately this study explores the relationships of radiography to the diagnostic process in dentistry so that the value of dental radiography may be more scientifically placed on the diagnostic continuum from noncontributory to essential.